This is a collaborative project with the aim of developing, validating and applying a quantitative measure of nerve regeneration to the study of factors that promote or regulate the rate and extent of axonal outgrowth in both peripheral and central nervous tissues. We have developed a quantitative fluorescent method based on immunochemical detection of phosphorylated neurofilament protein. The techniques has been validated by applying it to a study of sciatic nerve degeneration and regeneration subsequent to nerve crush. Studies are in progress to extend this technique to studies of spinal cord degeneration and regeneration subsequent to controlled crush injury.